# how to use component block

**URL:** <https://forum.fixtrading.org/t/how-to-use-component-block/12768>\
**Category:** General Q&A\
**Tags:** imported, 44-changes, xid\_165307\
**Created:** [January 29, 2012, 9:32am UTC](https://forum.fixtrading.org/t/how-to-use-component-block/12768 "2012-01-29T09:32:23Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![lswallowjun\_x](https://avatars.discourse-cdn.com/v4/letter/l/b9bd4f/32.png) [@lswallowjun\_x](https://forum.fixtrading.org/u/lswallowjun_x)\
**Post date:** [January 29, 2012, 9:32am UTC](https://forum.fixtrading.org/t/how-to-use-component-block/12768/1 "2012-01-29T09:32:23Z")

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Imported from previous forum

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**Author:** ![lswallowjun\_x](https://avatars.discourse-cdn.com/v4/letter/l/b9bd4f/32.png) [@lswallowjun\_x](https://forum.fixtrading.org/u/lswallowjun_x)\
**Post date:** [January 29, 2012, 9:32am UTC](https://forum.fixtrading.org/t/how-to-use-component-block/12768/2 "2012-01-29T09:32:23Z")

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Currently I am confused about the component block.  
Is there someone can give me a specific example to show me how to use component block.  
Thanks in advance  
Lswallow

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**Author:** ![hanno.klein](https://yyz2.discourse-cdn.com/flex010/user_avatar/forum.fixtrading.org/hanno.klein/32/38_2.png) [@hanno.klein](https://forum.fixtrading.org/u/hanno.klein)\
**Post date:** [January 30, 2012, 9:18am UTC](https://forum.fixtrading.org/t/how-to-use-component-block/12768/3 "2012-01-30T09:18:55Z")

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Component blocks are not relevant for a tag=value encoding unless they are repeating. Please provide more detail to your question. Non-repeating components allow to structure messages better and to re-use elements in multiple places, e.g. the block.

> Currently I am confused about the component block.  
> Is there someone can give me a specific example to show me how to use component block.  
> Thanks in advance  
> Lswallow

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<div class="post-metadata">

**Author:** ![lswallowjun\_x](https://avatars.discourse-cdn.com/v4/letter/l/b9bd4f/32.png) [@lswallowjun\_x](https://forum.fixtrading.org/u/lswallowjun_x)\
**Post date:** [January 31, 2012, 6:01am UTC](https://forum.fixtrading.org/t/how-to-use-component-block/12768/4 "2012-01-31T06:01:21Z")

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Thanks for your explaination first.  
I’m sorry I can’t understand what you have say clearly.Do you mean that I should insert these tags of the component block I need into my messages if it has repeating groups？if so,how should I do if it has no repeating groups.

> Component blocks are not relevant for a tag=value encoding unless they are repeating. Please provide more detail to your question. Non-repeating components allow to structure messages better and to re-use elements in multiple places, e.g. the block.
> 
> > Currently I am confused about the component block.  
> > Is there someone can give me a specific example to show me how to use component block.  
> > Thanks in advance  
> > Lswallow

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<div class="post-metadata">

**Author:** ![hanno.klein](https://yyz2.discourse-cdn.com/flex010/user_avatar/forum.fixtrading.org/hanno.klein/32/38_2.png) [@hanno.klein](https://forum.fixtrading.org/u/hanno.klein)\
**Post date:** [January 31, 2012, 8:10am UTC](https://forum.fixtrading.org/t/how-to-use-component-block/12768/5 "2012-01-31T08:10:45Z")

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I think your question is more basic in nature. Please take a look at the FIX 5.0 SP2 Errata Specification Volume 1 which explains the tag=value syntax, page 20-21 ([http://www.fixprotocol.org/documents/5905/FIX-5.0\_SP2\_VOL-1\_w\_Errata\_20110818.pdf](http://www.fixprotocol.org/documents/5905/FIX-5.0_SP2_VOL-1_w_Errata_20110818.pdf)).  
Some fields outside of repeating groups are required, most are optional. If it is a repeating group then the NoXXX field and the first field always need to be present. Additional fields may have to be present if the description contains a sentence like “Conditionally required when NoXXX\>0”. Otherwise you choose the fields you need to fulfill your business requirements. Component blocks that are non-repeating require no special treatment in tag=value syntax, they are just a list of (optional) fields in the message. If the component block is the first element of a repeating group then the first field of the component block is required because it also represents the first field of the repeating group.

> Thanks for your explaination first.  
> I’m sorry I can’t understand what you have say clearly.Do you mean that I should insert these tags of the component block I need into my messages if it has repeating groups？if so,how should I do if it has no repeating groups.
> 
> > Component blocks are not relevant for a tag=value encoding unless they are repeating. Please provide more detail to your question. Non-repeating components allow to structure messages better and to re-use elements in multiple places, e.g. the block.
> > 
> > > Currently I am confused about the component block.  
> > > Is there someone can give me a specific example to show me how to use component block.  
> > > Thanks in advance  
> > > Lswallow